The Iron Gate is a gorge on the Danube River. It forms part of the boundary between Serbia and Romania. In the broad sense it encompasses a route of 134 km (83 mi); in the narrow sense it only encompasses the last barrier on this route, just beyond the Romanian city of Orsova, that contains a hydroelectric dam, with two power stations, Iron Gate I Hydro Power Plant and Iron Gate II Hydro Power Plant .

The gorge lies between Romania in the north and Serbia in the south. At this point, the river separates the southern Carpathian Mountains from the northwestern foothills of the Balkan Mountains. The Romanian and Hungarian names, Porþile de Fier and Vaskapu, literally mean "Iron Gates" and are indeed used to name the entire range of gorges. An alternative Romanian name for the last part of the route is Clisura Dunarii, "Danube Gorge".

In Serbia the gorge is known as Ðerdap, with the last part named Ðerdapska klisura. The Romania side of the gorge constitutes the Iron Gate Natural Park, on the other bank, in Serbia, is located the Ðerdap natural park.